James Lipton remembers Robin Williams: 'His gift was the most mysterious of all gifts'

Until Robin Williams won an Academy Award for his 1997 dramatic role in “Good Will Hunting,” many thought of the late star as "just" a comedian. But James Lipton, host of Bravo’s “Inside the Actors Studio,” said Williams’ brilliance as an actor was evident at every stage of his career — even when he was playing for laughs.

"Great comedians have to be great actors," Lipton explained in a Tuesday interview with TODAY's Matt Lauer. "An actor reaches inside his soul ... deeper than we can go on our own and brings out something that's mysterious and a total surprise that we can't possibly predict, but that which is inevitable. (Williams) could do that. He could do that as a comedian; he could do that as an actor.

"His gift was the most mysterious of all gifts," Lipton said. "It was genius. Genius is inexplicable. ... You can teach craft. You can teach technique. You can't teach genius."

You couldn't get Williams to contain that brilliant energy, either, Lipton recalled. When Williams appeared on "Inside the Actors Studio" in 2001, the Oscar winner was so fired up that Lipton could barely speak.

"He came out on the stage, I introduced him to our students ... then he took off," Lipton laughed. "It was six minutes before I could ask the first question." Williams' madcap marathon appearance ended up becoming the series' first two-hour episode — and viewers' all-time favorite.

Lipton recalled that when he asked Williams his standard interview question about imagining an afterlife, Williams expressed hope for eternal laughter and riffed on telling jokes with God at the pearly gates.